1. Technical Field
The present invention relates to a component transferring apparatus and an IC handler.
2. Related Art
In general, a testing apparatus (an IC handler) that inspects electronic components such as semiconductor chips includes a plurality of transferring robots to transfer the components. The transferring robots transfer an electronic component before inspection into an inspection socket to measure quality of the component, and then, retrieve the inspected component from the socket.
Specifically, for example, a supplying robot sucks and holds an electronic component before inspection and then releases the component to mount in a supply pocket of a shuttle. Next, the shuttle moves the electronic component to a position where a measuring robot is located to suck and hold the component. The measuring robot transfers the electronic component before inspection from the shuttle to the inspection socket. After inspection is finished, the measuring robot again sucks and holds the component inspected to transfer it from the inspection socket into a retrieval pocket of the shuttle. Then, the shuttle moves the inspected component to a position of a retrieving robot, where the retrieving robot releases the component into a retrieval tray in accordance with an inspection result.
When the robots sequentially transfer the electronic component to the inspection socket and the pockets, the component is needed to be mounted in a predetermined position in each of the inspection socket and the pockets. Particularly, in order to mount the electronic component in the inspection socket, it is necessary to suitably contact measuring terminals of the inspection socket with terminals of the electronic component. Thus, it is desirable to minimize a relative positional deviation between the electronic component and the inspection socket. Additionally, when the component is mounted in each pocket, reducing a relative positional deviation between the pocket and the component is desired.
In order to reduce the relative positional deviation between the electronic component and the inspection socket or the like, there is known a method. In this method, first, a camera photographs the electronic component, the inspection socket or the like to obtain image data. Next, an image processing of the data is performed to calculate the relative deviation amount, and then, based on a calculation result, positional correction is performed by only the relative deviation amount.
For example, there is disclosed a method for correcting a relative positional deviation between an electronic component and a socket or the like (e.g. WO 2003/023430). In an IC handler employed in the method, when an electronic component before inspection is transferred from a shuttle to a test device, a camera located between the shuttle and a test socket (the test device) photographs the component sucked and hold by a transfer head of a transferring apparatus. Additionally, a camera equipped with the transfer head photographs the test device. A controlling device of the IC handler performs the image processing of each image data obtained by the above photographing operations to calculate a relative deviation between the electronic component and the test device. Then, based on a calculation result, the controlling device operates an adjustment mechanism of the transferring apparatus to adjust a position of the transfer head so as to correct the relative deviation between the component and the test device.
Additionally, when transferring the inspected electronic component from the shuttle to a tray, a pick and place (P&P) robot sucks and holds the component to transfer from the shuttle to the tray. The IC handler moves the P&P robot to above a camera located within a movable range of the robot to allow the camera to photograph the component sucked by the robot. The controlling device of the IC handler performs the image processing of image data obtained from the photographing operation to calculate a relative deviation between the component and the tray. Then, based on a calculation result, the controlling device operates an adjustment mechanism of the robot to correct the relative deviation between the electronic component and the tray.
In the above method, however, in order to calculate a relative deviation between the transfer head and the test socket, the camera of the transfer head is needed to be located with a high precision. Furthermore, when a relative positional relationship between the transfer head and the camera is changed due to thermal expansion and contraction, vibration, or the like, it is impossible to detect the change to reflect a detection result in the calculation of the relative deviation.
Thus, there is disclosed a method for directly photographing an electronic component and a test device (e.g. Patent No. JP 3063899). The method provides an IC handler including a camera mounted on a supporting member with a mirror. The mirror is located between the electronic component and the test device to reflect both of the component and the test device thereon. When the component before inspection is hold by a transferring apparatus and located above the test device in a manner facing the test device, the camera simultaneously photographs both images of them reflected on the mirror.
However, in the above method, it is complicated to locate and adjust the mirror such that both the component and the test device can be reflected on the mirror. It is also difficult to locate and adjust the camera in order to photograph their mirror images. Moreover, when the electronic component and the test device are photographed, the mirror is located therebetween. Accordingly, locating and withdrawing the mirror is a time-consuming task.